铁路辙叉用V+N微合金化高锰钢的设计及其强韧化机制

    Design of V+N Micro-alloyed High Manganese Steel Used for Railway Frogs and Its Strengthening Toughening Mechanism

    • 摘要: 高锰钢凭借其优异的加工硬化性能和耐磨性被广泛应用于铁路辙叉领域,但高锰钢材料的屈服强度较低,导致其服役寿命较低。因此,提升高锰钢材料强韧性对提高铁路辙叉使用寿命具有重要意义。试验采用V+N微合金化思路促进高锰钢基体组织中析出大量V(C,N)纳米析出相,显著提高高锰钢材料的屈服强度和硬度。结果表明:与传统Mn13相比,V+N微合金化高锰钢的屈服强度提升39%,达到535 MPa;伸长率略有降低,为44.3%。纳米析出相一方面通过阻碍位错运动提升材料的屈服强度,另一方面也会抑制孪晶的产生,提高了孪晶产生的临界应力,促使孪晶在更高应变下产生,使孪晶诱发塑性作用(TWIP)持续到更高应变阶段,从而赋予材料较好的塑性。

       

      Abstract: High manganese steel with its excellent work hardening properties and wear resistance is widely used in the field of railway frogs. However, the low yield strength of high manganese steel results in a relatively short service life.Therefore, enhancing the strength and toughness of high manganese steel is significant for extending the service life of railway frogs. V+N microalloying approach was employed to promote the precipitation of a large number of V(C, N) nanoscale precipitates in the high manganese steel matrix, thus significantly increasing the yield strength and hardness of the material.The results show that compared to the traditional Mn13 steel, the yield strength of V+N micro-alloyed high manganese steel is increased by 39%, reaching 535 MPa, the elongation rate is slightly reduced, which is 44.3%. The nanoscale precipitates, on the one hand, enhance the material’s yield strength by hindering the movement of dislocations, and on the other hand, they suppress the formation of twins, raise the critical stress required for twinning. This encourages the occurrence of twins at higher strains, which make the twinning-induced plasticity effect(TWIP) to continue to higher strain stages, thereby endowing the material with better plasticity.

       

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